This is a welcome addition to the rock documentary sub-genre. It’s not the most original of set ups – the build up to X Japan’s Madison Square Garden concert is interspersed with the band’s story – but it is refreshing. Both from the views that come from the band and that it covers a country where rock while now common was once seen as almost deviant.

The documentary pivots around Yoshiki, as X Japan’s main songwriter, drummer, leader, and there are several long intimate interviews with him. But there’s also lead singer Toshi who as childhood friend formed the band. Their close friendship is caught in a couple of sequences as they discuss the old days. This friendship lasted through the band’s split in 1997, at the height of their success, and Toshi’s subsequent involvement with a cult. The two eventually getting back on terms in 2007, reforming X Japan in 2008.

X Japan, despite having sold 30 million albums, sold out enoromdomes worldwide and absolutely adored by their fans, show little sign of out of control egos. As is evinced in a very touching scene where band leader Yoshiki is leaving a graveyard and is recognised by some fans. He patiently talks to them and signs autographs, treating them - and they him – with great respect.

Death however permeates this documentary, and specifically death by suicide: Yoshiki’s father and two band members died by their own hands. The cultural aspects aren’t examined in any great detail but Yoshiki’s comments that it’s a selfish act, say much. The footage of guitarist Hide’s funeral is astonishing in the size of it and the reaction of the fans.

It’s not all doom and gloom. Director Stephen Kijak also captures the absurdity of the rock ‘n’ roll circus. One of the supposed drawbacks of them being able to break the USA was their lack of English language skills, which is posed to them in a particularly gormless manner during a press conference. Gene Simmons has his own usual robust view but credit to the band that they brushed all this nonsense off. There’s also a comical exchange with a doctor and a bemused Yoshiki about changing his drum technique.

There’s also X Japan’s early days, when the influence of LA’s 1980’s hair metal scene was obvious though they went two or three times further in the hair stakes with colourful coiffures as high as they are tall. The concert footage is telling too from small venues to massive arenas and spectacular lights and explosions, while the music progresses from sub Mötley Crüe to a more symphonic/power metal sound.

What becomes clear over the course of the film is that X Japan are not just wannabee LA scenesters but also a reaction to Japan’s quite conservative society. They saw themselves - and perceived by others - as outsiders, breaking conventions. They became accepted and popular, not by throwing things about and agitation just simply being themselves and playing their music.

They broke through to become a positive phenomenon, and up to a certain point, role models. There was some aberrant behaviour but hey, they are successful rock stars and that just goes with the territory!

We Are X will be available on Home Ent from 22nd May.